Why is “Administrative Leave” (paid) the norm?

(USA)

Time and time again, a ‘peace’ officer abuses their power, violates individual right, racially profiles, *the list goes on and on . . . *

Why do these agencies keep placing the f#ck ups on PAID time off?

There are instances where the punishment is slightly worse or better, like unpaid leave, or other duties, etc.

But to me and plenty of others, the punishment is not equal to the offense. Shouldn’t they be fired forever or something?